it is odd. I'm actually a semi-literate, totally informally trained greek speaker who can get by with everyday greek. As with Italian, which I'm also currently learning, DuoLingo tends to give some odd words to learn. "bullhorn" was in the first lesson. Really? Thirty years of everyday conversational greek and I've never had occasion to use "bullhorn". What's up with that!
For keyboard languages on an android tablet, the SwiftKey app works good. There are two things I had to look up: to switch languages on the keyboard, swipe left or right on the space bar and to minimize the keyboard use the back button for the tablet. So for this app you can have many languages loaded but can only swipe between 3 at a time when the keyboard is in use with an app.